Can't do anything

Speech problem of my wife is not getting any better. Everyday she fails to say exact words to describe a thing or a situation. No sign of physical difficulties as yet. But her mind seems to be not clear. I read some bad descriptions about language problems of brain cancer patients. For example, cases where the patient finally gets to the point that she/he cannot understand what is being said by other people let alone inability to express their thoughts. It just makes me shiver to imagine such situation.

I cannot get myself to work. I cannot write anything. I cannot think about the better future. I cannot make my mind calm. I cannot do anything.